# CVE-2026-93353: copyparty SFTP Volume Restriction Bypass via mkdir/rmdir/chattr Handlers

> Authenticated SFTP users can bypass volume restrictions to create, delete, or truncate files outside authorized directories via symlink traversal.

- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Sep 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-3465-46r4-pj75

## What is CVE-2026-93353?

CVE-2026-93353 is a low-severity path traversal vulnerability in 9001 copyparty, published on 24 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

copyparty contains a volume restriction bypass vulnerability in its SFTP front end that allows authenticated SFTP users to create, remove, and truncate arbitrary paths outside permitted volume boundaries by exploiting three handlers that bypass the xvol volflag enforcement. The _mkdir, _rmdir, and _chattr handlers construct destination paths using vfs.get(), vn.canonical(), and os.path.join() without invoking the chk_ap access check, enabling attackers to traverse symlinks leaving a volume's top directory and perform unauthorized file creation, deletion, or truncation via SSH_FXP_SETSTAT operations on paths outside any volume the account is authorized to access.

Weakness: CWE-59 (Improper Link Resolution Before File Access), CWE-424 (Improper Protection of Alternate Path)

## Which versions are affected by CVE-2026-93353?


## How do I fix CVE-2026-93353?

No fix has been published for CVE-2026-93353 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-93353 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-93353 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93353 and fix it if it is affected.

What it is: CVE-2026-93353 is a low-severity path traversal vulnerability in 9001 copyparty, published on 24 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-93353 exists.

Affected product: 9001 copyparty. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-93353/ (Markdown: https://insights.sbomify.com/CVE-2026-93353/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93353
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93353
- OSV: https://osv.dev/vulnerability/CVE-2026-93353

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93353/
Summaries are generated and may contain mistakes; the official description above is the record.